The data pattern is as follows. How to use mapReduce to count the number of children whose sex is male? (Children’s Life Unknown, Data Structure Touching! _! )
There are about millions of such data in a db set.
{
"name": "Little Lean Oil to Rikuban",
"Xiao Xin": {"
"Name": "Xiao Xin",
"Age": "6",
"Gender": "Male"
},
"Nini": {"
"Name": "Nini",
"Age": "7",
"Gender": "Female"
},
"Hazama jade": {"
"Name": "Hazama jade",
"Age": "7",
"Gender": "Male"
},
"A Dai": {"
"Name": "A Dai",
"Age": "6",
"Gender": "Male"
},
.
.
.
.
.
}
For this data structure, MapReduce is used for statistics. I wonder if the landlord has found a solution yet? First of all, it is impossible to determine how many images a record has.
"A Dai": {" "Name": "A Dai", "Age": "6", "Gender": "Male" }
This kind of data, and map key you are not fixed, so it is difficult to locate the gender field. The realization I can think of is to do statistics in the program, that is, to take them out of the database. If the landlord has implemented MapReduce statistics, I hope to share the implementation, thank you.